Generally, a tracked machine, such as an electric rope shovel, includes a drive assembly for transferring motive power from one or more of an engine, an electric motor, and/or a transmission system to a ground engaging track of the machine. In some embodiments, the drive assembly includes a sprocket mounted on a drive shaft thereof. In other embodiments, the sprocket may be mounted on a final drive planetary assembly. The sprocket provides interconnection with the track and transfer of motive power therebetween.
The sprocket may experience accelerated wear due to friction mainly due to repeated contact with the track, contact with debris deposited around the sprocket, operation in harsh environment with the ground, and so on. As a result, the sprocket may require frequent replacement in order to provide optimal contact between the sprocket and the track. In a situation when the sprocket may be mounted on the drive shaft, in order to provide access to the sprocket for repair/replacement, the drive shaft may have to be disassembled from the drive assembly in order to provide access to the sprocket for repair/replacement thereof.
The drive shaft may be mounted on a set of bearings within the drive assembly. In some situations, the drive shaft may be affixed to the bearings via an interference fit therebetween. As a result, in such a situation, the drive assembly may have to completely dismantled in order to disassembly the dive shaft along with the bearings for providing access to the sprocket. This may lead to increased repair time, machine downtime, labor cost, physical effort, and so on.
In some situations, the drive shaft may be mounted on the bearings with a loose fit therebetween. This may provide limited dismantling of the drive assembly in order to disassemble the drive shaft and the sprocket from the drive assembly without the bearings. However, the loose fit may result in increased shaft movement, increased seal movement, increased noise and/or increased friction between contacting surfaces of the drive shaft and bearings, such as an outer surface of the drive shaft and an inner surface of the bearings, and so on. As a result, the drive shaft, the bearings, the seals, drive couplings, and so on may experience accelerated wear leading to frequent replacement, increased replacement costs, and so on.
Also, in some situations, one or more teeth or sections of the sprocket may be worn out or damaged prior to remaining teeth or sections of the sprocket which may have some usable life remaining before complete wear of the sprocket. In such a situation, the complete sprocket may have to be replaced, in turn, leading to reduce component usability, increased replacement cost, and so on. Hence, there is a need for an improved sprocket for the drive assembly.
U.S. Published Application Number 2013/0038119 describes a sprocket assembly for a vehicle having a chassis and at least one endless track for engaging a ground surface. The track is movably coupled to the chassis and driven by a sprocket assembly. The sprocket assembly includes at least one sprocket segment, a hub rotationally coupled to the chassis, and a fastening system configured to displace some material portion of the sprocket segment when the sprocket segment is attached to the hub.